Are you planning a single throttle body to feed both cylinders via a common manifold/plenum? Like a car?

Yes sir. The TB mounts to the intake port of the blower and then will have a manifold/plenum that runs from the blower output directly to the heads. Alex and I will be fabricating the manifolds needed.

Just a quick thought about this is that the 45mm is just enough to feed both cylinders at once.With a blower on it, you can make it bigger and not sufferHowever, the cylinders feed on different strokes, so technically you would never have to feed them both at the same time. So the size could technically be smaller. As long as you have enough plenum volume, and boost, that should feed plenty. If you feel more comfortable with bigger, then it shouldn't hurt anything when there is boost coming in from the blower.Even though we don't have flow numbers yet, that size port is likely to flow near what the Fireball flows. So probably a little less than 200 cfm per intake.Maybe 50% more than that for boost, so seat of the pants figure 300 cfm for each intake, so max blower output of 600 cfm. Theoretical 150 hp potential at those figures, if it could be attained and hold together. Not sure it would. But it might. It' s not having to run for very long.

The 50mm could theoretically flow 444 cfm normally aspirated and uncompressed. That's more than double what each port would flow normally aspirated. Compressed would flow more.

Here she is! Quite literally, the Chiefs significant other half. And I'm sooooo freaking happy! Shortly before I got rid of this bike, I had got caught in a terrible hail storm that had left about 2 dozen bruises on my body and a DESTROYED instrument cluster. I needed a speedo and so I ended up buying this Koso DB-01R Multi-Function Electronic Speedometer.

I liked it because it was a compact all-in-one-unit and was under $200. It's designed for off-road use and is labeled as "waterproof" but never really thought about it. Well, I completely forgot that I even bought that thing until I was on my way to pick up the bike. When I got there, my buddy was telling me how when it had flooded the water was so deep that all he could see was the corner of the mirror sticking out of the water. I started thinking "Man. Maybe the swingarm and wheels are the ONLY good thing left on this bike." No matter, I loaded up the bike and brought it home. Out of curiosity, I threw the battery on the charger for about a half hour just to see what would happen and that son of a bitch turned right on! Guess who will be getting a letter of praise for their product? I now have a digital speedometer for the Chief that will read up to 224mph!

We have the baseline flow chart for the 700 twin.Since the ports and valves appeared unmodified, this is probably a generally representative flow chart for the RE twins of that era.Testing was done at 28" H2O on Mondello's Superflow Flow Bench.

The max lift we tested of .400" was as far up as the stock valve gear would allow, before the retainer was banging against the valve guide, so no higher lift testing was possible with unmodified valve gear.

In the plan for this head is to establish a new max lift height via custom valve train parts. While the flow numbers appear small, remember that this is a pair of 350cc cylinders, and the ports and valves are smaller too, to suit the normal application of this engine on the street in 1958. It is a bit behind the standard Bullet with the 500 cc engine, but not too far back. It might not be able to come up to Fireball flow standards, due to the fact that it has 2 smaller cylinders and smaller everything for each intake, but it should do quite well after modding, and the supercharger will have to do the rest.

Enjoy the info!Not many places to find this kind of info on these old engines.

Awesome! Thanks so much Tom! I had a great conversation with you today. It definitely seems like we're on the same page and you have enlightened me with new found information. I have really high hopes for this build. I truly believe that with yours and Mondello's work combined with the supercharger we should be able to break 100hp at the crank which is UNHEARD OF for these motors. But I think we're on the right track.

I finished stripping down the GS550 yesterday. The frame is now bare except for the motor which is only being held in buy 4 bolts, just need an extra set of hands to yank it out. Looks like the swingarm and wheel should switch right over to the Chief with minimum modifications. I haven't been able to compare the 2 side by side yet, but it looks like the width of the swingarms where the pivot bolt mounts to the frame are about the same width too. I'm pretty sure I can get it bolted right up with maybe a couple of bushings for the pivot point. I'll just need to weld in an upper shock mount to mount the mono shock in the center of the seat area. The best part of using this swingarm is that aside from the mounts being close to the same sizes, the GS swingarm is exactly 5" longer than the RE swingarm. This is great because, because to stay within the SCTA rules, I'm allowed to stretch the bike a TOTAL of 10% more than the original factory axle to axle specs. This gives me a MAX of a 6" stretch on the bike. The GS swingarm being 5" longer than factory should get me long enough to help stabilize for high speeds, but without breaking the rules. Or further more, not being so close to within the rules that the officials may question the legality of my build.

It will take a little more work to get some custom rear sets mounted nice and far back. They will be mounted up about 6.5-7" ahead of the rear wheel axle (again, rules state that the foot mounts must be AT LEAST 6" in front of the rear axle), which will move them back about 14" from the original foot peg location. I will also be mounting clip-on bars that will be mounted as far down on top of the lower triple tree as possible. This combination should allow my 6' tall body to lay out nice and flat on the bike with a real tight body tuck. This is important as I've decided to break my first few records without a fairing, so body positioning is going to be crucial for trying to cut through that salty air.

Nice job Scottie this is going to be a real project. Are you still feeling better with the new diet? ERC

Oh God yes! Thanks! I still have a crappy day now and then, but I no longer spend every moment of everyday feeling like I'm going to throw up. My stomach is still healing up and not 100% but I feel so much better now.

And yes! I think I got lucky with that swingarm. I'm just happy to be able to have a rear disc brake, aluminum wheel and a mono shock with a preload damper. I'm about to go out to the garage and look a little more closely. I'm going to take some more measurements and see how close the mounting area is going to be the same.